2015 ISAKOS Biennial Congress ePoster #401

Evaluation of the Efficacy of Intra-Articular Injections of Hyaluronic Acid for Medial Gonarthrosis By Using T1rho and T2 Mapping Images

Hiroaki Nishioka, MD, PhD, Kumamoto City JAPAN
Eiichi Nakamura, MD, PhD, Kashimashiki-Gun, Kumamoto JAPAN
Hiroshi Mizuta, MD, PhD, Kumamoto City JAPAN
Department of Orthopaedic Surgery, Faculty of Life Sciences, Kumamoto University, Kumamoto city, Kumamoto, JAPAN

FDA Status Not Applicable

Summary: Quantitative evaluation can be performed using MRI, which can detect changes in the cartilage matrix. The results of our study demonstrate the recovery of proteoglycan in the cartilage matrix because the T1rho values of KL grade 2 subjects decreased after three months of IAI-HA compared to baseline.

Abstract:

Purpose

Hyaluronic acid (HA) showed chondroprotective effects on the articular cartilage in an experimental study. However, the efficacy of HA in clinical practice is debatable. The aim of this study was to verify, using quantitative evaluation, whether intra-articular injections of hyaluronic acid (IAI-HA) have chondroprotective effects. Quantitative evaluation can be performed using MRI, which can detect changes in the cartilage matrix.

Materials And Methods

Patients with medial gonarthrosis were evaluated on the Kellgren-Lawrence (KL) classification scale. There were 8 KL grade 2 and 7 KL grade 3 patients included in the study. The mean age was 66.4 years. We started the patients on a regimen of IAI-HA once a week for 5 weeks, followed by injections once every 2 weeks for 3 months. Quantitative evaluation of articular cartilage using sagittal T1rho and T2 mapping images was performed before intervention and at three months after IAI-HA. The regions of interest (ROIs) in the T1rho and T2 mapping images were set at the full-thickness cartilage in each medial femoral condyle (MFC) and medial tibial plateau (MTP). T1rho and T2 relaxation times in the ROIs mapped to each image were measured. For zonal evaluation, the ROIs were divided into two equalized layers (superficial and deep).

Results

In full-thickness evaluation of KL grade 2 subjects, the T1rho value at three months after IAI-HA showed a significant decrease compared to before IAI-HA in both MFC and MTP (P < 0.05). There was no difference in T2 values in both MFC and MTP. In zonal evaluation of KL grade 2 subjects, the T1rho values of the superficial layer in MFC and MTP were significantly different between the baseline and three months after IAI-HA (P < 0.05). Similarly, T2 values of the deep layer in MFC showed a significant decrease (P < 0.05). In full-thickness and zonal evaluation of KL grade 3, there was no difference in T1rho and T2 values in both MFC and MTP.

Discussion

Jubb et al. reported that the change in joint space width was significantly different between the baseline and at 52 weeks after IAI-HA in the group with progressive joint space narrowing. However, there was no difference in the joint space width of the group without progressive joint space narrowing. The results of our study demonstrate the recovery of proteoglycans (PG) in the cartilage matrix because the T1rho values of KL grade 2 subjects decreased after three months of IAI-HA compared to baseline. Additionally, our study was not able to confirm a similar effect in KL grade 3 subjects. The IAI-HA restored the PG concentration in the cartilage matrix and has a chondroprotective effect for early gonarthrosis.